【题目】Don't worry. They ______ to consider your advice. Let me remind them of it now.
A.could forget
B.could have forgotten
C.should have forgotten
D.should forget

【答案】B
【解析】考查含情态动词的完成式。句意：不要担心。他们可能已经忘记了考虑你的建议。我现在就来提醒他们。could have done(1)可能已经做了某事(2)本来能做而没有做。故选B。